ALERT: document.URL = about:srcdoc
ALERT: document.baseURI = http://example.com/base/URI/of/parent.html
ALERT: After <base> element:
ALERT: document.baseURI = http://example.org/base/URI/from/child/base/tag.html
A srcdoc document should inherit its document.baseURI from its parent (but not its document.URI).